According to Luke (3:36-38) the Noachan Flood took place in the 10th generation after Adam, who was at the beginning of Creation (Mark 10:6). If we compute the ages of people given in Genesis 5 we see that the Flood took place 1656 years after Creation, the year that Methuselah died.
After the Flood Noah's sons lived long enough to overlap with Abraham and Isaac. Isaac was 110 years old when Shem died. The Flood was thus about 2,500 years BC.
These dates are of course scorned by uniformitarians - geologists who believe in gradualism and evolutionists who need millions of years for life to 'progress' from microbes to man. Honest science however shows that the earth is young - thousands not millions of years old - so we do not need to doubt the history of the Flood as given to us by God in His Word, the Bible.

I am a Christian, but, honestly, I cannot ignore science. (Forgive my English, not my native tongue.)
About twelve thousands years ago the Sahara still was habitable for many animals and people – bones found there anyway. The landscape was more green in the fertile crescent and in the valley of Euphrates and its neighborhood.
The African animals were still more abundant there, than today. With the melting of the ice lots of water rushed down from the north from the Caucasian areas. I think the flood was a local event recorded even in Gilgamesh.
Even the bible indicates, for God a year like a thousand for a man. Also for the age of the Earth there is something you cannot overlook. There are radioactive atoms for which we know its half life. These radioactive atoms came from formerly exploded stars. There is no magic in this, at all. If we reject radioactivity and half life, then science is just hokuspokus – which I don’t think so.
No one can say the flood took place at a given date, when written history is not even 4000 years old. Spoken history bear many truth, just think about the Greek legend that became fact, like the palace of Knossos or Troy.
For the Flood, I think, the answer relies in the hand of geologists and not theologists. In the spoken history facts entwined with fairy tales. Jesus himself spoke in parables, which sometimes, gave discomfort even to his disciples. If God spoke in such a language, why don’t we think it was so in the First book of Moses.
Regards,
Simon